You must make your site as easy to use as possible. Potential customers won't waste their time trying to work out how to use your site. If it's not immediately obvious how they can get what they want, they won't do it. Not only should the UI (User Interface) be optimized, but the site itself should be designed to make it as easy as possible for visitors to convert to customers - i.e. it should be optimized for conversions.
A pay-per-click campaign It gets expensive to buy sponsored links from the Google’s Adwords or Yahoo’sSearch Marketing services. But your competitors are undoubtedly doing it. So if you’re not, it’s unlikely you’ll be competitive (unless you have a very compelling product or price). As online competition has increased, a PPC campaign has become essential.
You distinguish yourself from the sea of competitors by creating great content. I'm not joking either. Creating high quality, highly relevant, engaging and SEO enhanced content is arguably the most important marketing exercise you can undertake. It takes a while for your content to be indexed by Google, but once it is the effects are cumulative (the more content you add, the more traffic you generate) and persistent (unlike online advertising, which offers no long term benefits).
Recall that at the start of this article I mentioned how easy it was to start an online business? The other side of that coin is that every man and his dog is doing exactly that. Online consumers are jaded, and impatient. It is not easy to convince them to spend their dollars with your relatively unknown startup because there are millions of relatively unknown startups, and most of them are complete rubbish.
Realize a couple of key facts: A) the prices for e-commerce software have fallen, so you don’t need to spend a fortune unless your needs are complicated, and B) many of today’s e-commerce packages include a full range of tools in one package, from an inventory management system to marketing tools. Many of today’s merchants prefer this “all-in-one” approach because it makes life simpler.